His agility numbers were good at the combine. Top 10. Better than Diallo, Frank Jackson and several other guards. And that was at 241 pounds. If he works on his technique moving laterally shouldn't be a problem.
I do agree though that there are things he needs to improve. His shot selection and decision making isn't very good at times when I've seen him play. And he needs more moves off the dribble imo. He relies a little too much on his strength and straight line drives to the basket at this stage. All the questions that I have about him are things that he can work to improve though. That's a positive. I like him a lot.